Tag Archives: Java

NoSQL

Not only SQL (NoSQL) databases using different kind of technics for storing and retrieving data compared to classical relational databases like DB2 or Oracle. They emphasis more on scaling and storing different kind of data then on ACID or CAP support.

Type of NoSQL databases

NoSQL databases can be divided into five different types:

Column

Tuple of three values: Unique name, value and timestamp

Document

semi structured data in documents

Key Value

dictionary of key value pairs

Graph

graph oriented system of nodes with properties and edges

Multi Model

mixture of data models with one backend

MongoDB belongs to the document based NoSQL databases.

HBase as part of apache Hadoop belongs to the column based NoSQL databases.

MongoDB

MongoDB is a open source document database mainly written in C++ as native application. The MongoDB Inc. is the company behind that product and offers commercial versions, suppport, etc.

License is A GPL 3.0

Features

Document oriented Database

aggregation

Sharding

Replication

Indexing

automatic fail-over

Apache Hadoop

The Apache Hadoop is a umbrella for different software projects to store and process distributed large data sets. It’s open source and maintained by the apache community.

License is Apache 2.0 license

HDFS

The Hadoop distributed file system (HDFS) is a distributed storage system written in java suitable for storing large files in a scalable and fault tolerance cluster.

With the new Beta 1 of the Vaadin Addon Vaadin Spring Boot you can use Spring Boot as base framework for your Vaadin UI. The following example application use Spring Data as service layer on top of a mongoDB as NoSQL database. Blackboard is used as generic event sub system inside the Vaadin UI. Complete Source Code is available on github.

With the Servlet 3.x API as part of JEE 6 come with the possibility to configure a java web application by writing a java class instead of having a web.xml file inside the WEB-INF folder. My sample apache cxf project has a web.xml with a spring configuration listener and a cxf servlet mapping. I use jetty for integration tests inside maven builds and tomcat as application server for deployment and running the web application. The web service sample use Spring 3.1 and Apache CXF 2.6.2.

Step 3: Configure Maven War Plugin to ignore web.xml

Java Configuration

Step 4: Write Configuration file

Write a class that implement the WebApplicationInitializer interface from Spring Web and override the onStartup Method. Inside that you have to setup spring application context and map the servlet classes to url patterns:

Step 5: Delete web.xml

Delete inside WEB-INF folder the web.xml file and use the mvn clean command to remove it from target folder.

Step 6: Testing

run mvn package to build the war file in your project. Download and extract tomcat 7.x for testing your war file. Put the war file in the webapps folder and run your server with the startup.bat in the bin folder of tomcat.

was the line above and i had recently updated firefox on my ubuntu 12.01 server to version 15 by normal updates. The maven dependent selenium plugin version was still the same when i got the error. After updating to the latest version everything works as before: